JP5429565B2 - Vehicle height detection device - Google Patents

Description

  The present invention relates to a vehicle height detection device, and more particularly to a vehicle height detection device configured to detect a vehicle height using a device provided in a vehicle such as a parking assistance system.

Vehicle height sensors are used in various vehicle systems such as headlamp optical axis control and parking assist control.
For example, in the optical axis control device for a headlamp described in Patent Document 1, a plurality of ultrasonic sensors (vehicle height sensors) are arranged below the cross member toward the ground. Moreover, in the parking assistance apparatus of patent document 2, the ultrasonic sensor (vehicle height sensor) is provided toward the ground at the vehicle rear lower part. In Patent Documents 1 and 2, by using an ultrasonic sensor, the vehicle height can be directly obtained by measuring the distance from the ground using sound waves.
Moreover, in the parking assistance apparatus of patent document 3, the vehicle height sensor is provided in the stabilizer. With the vehicle height sensor of Patent Document 3, the vehicle height can be detected by detecting the rotation angle of the stabilizer.

JP 2007-176296 A JP 2002-293196 A JP 2004-114840 A

  However, since conventional vehicle height sensors such as those described in Patent Documents 1 to 3 are disposed near the ground, a structure for protecting them from flying stones is required. For this reason, in addition to the cost of the sensor alone being expensive, it is necessary to make the sensor strong and strong, which increases the vehicle price and increases the weight.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a vehicle height detection device that can be configured at a low cost without a weight increase with a simple configuration.

In order to achieve the above object, the present invention provides a vehicle height detection device for detecting vehicle height, which is fixed to a vehicle body, and is a distance measurement means for measuring a horizontal distance to a measurement object around the vehicle, and is fixed to the vehicle body. The measurement object is based on the imaging means for imaging the measurement object around the vehicle, the image data of the predetermined part of the imaged measurement object, the horizontal distance, and the positional relationship data between the distance measurement means and the imaging means. Vehicle height calculating means for calculating the ground height of the imaging means relative to the predetermined portion and calculating the vehicle height from the ground height , the vehicle height calculating means being viewed from the imaging portion of the imaging means based on the image data. And calculating a second horizontal distance between the imaging unit and the predetermined unit in the optical axis direction of the imaging unit of the imaging unit based on the horizontal distance and the positional relationship data. Using direction angle and second horizontal distance It is characterized in that to calculate the ground clearance.

According to the present invention configured as described above, the vehicle height calculation means performs calculation processing based on the image data and the horizontal distance from the imaging means and the distance measurement means, and the positional relationship data between the distance measurement means and the imaging means. The vehicle height can be calculated. Thereby, since the component of this invention can be comprised using the existing system (parking assistance system) of a vehicle, it becomes possible to obtain | require vehicle height, without providing a dedicated vehicle height sensor. . Further, according to the present invention configured as described above, the vehicle height can be easily calculated based on the image data obtained by the imaging means, the horizontal distance obtained by the distance measuring means, and the positional relationship data between the imaging means and the distance measuring means. Can do.

  In the present invention, preferably, the predetermined part of the measurement object can be a contact part of the measurement object with the ground. According to the present invention configured as described above, the predetermined portion of the measurement object is a contact portion with the ground of the measurement object, so that the part can be easily recognized and specified from the image data. .

  In the present invention, preferably, the vehicle height calculation means calculates a left-right angle of a predetermined part of the measurement object viewed from the image pickup unit of the image pickup means based on the image data, and further uses the left-right angle. A second horizontal distance is calculated. According to the present invention configured as described above, the vehicle height can be calculated even when the measurement object is located outside the extension of the optical axis of the imaging means.

  According to the present invention, a vehicle height detection device can be provided with a simple configuration without providing a dedicated vehicle height sensor.

It is explanatory drawing of the vehicle height detection apparatus by embodiment of this invention. It is explanatory drawing of the vehicle rear part by embodiment of this invention. 1 is a configuration block diagram of a vehicle height detection device according to an embodiment of the present invention. It is explanatory drawing which shows the image data by embodiment of this invention. It is a figure explaining the measurement condition of the vehicle height detection apparatus by embodiment of this invention. It is a figure explaining the measurement condition of the vehicle height detection apparatus by embodiment of this invention. It is explanatory drawing which shows the image data by embodiment of this invention. It is a processing flow of the vehicle height and inclination angle calculation process by embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 8.
As shown in FIG. 1, the vehicle 1 of this embodiment includes a vehicle height detection device 10 that calculates the vehicle height of the vehicle 1 and the inclination angle in the front-rear direction.
The vehicle height detection device 10 includes an ECU 20 mounted on the vehicle, a back monitor camera 30 fixed to the rear portion of the vehicle, and a plurality of sonars 40 (40a, 40b, 40c, 40d).

  The vehicle height detection device 10 of the present embodiment uses an existing parking assistance system mounted on the vehicle 1. That is, the ECU 20, the camera 30, and the sonar 40 are components of the parking support system.

  The ECU 20 includes a CPU, a memory, an input / output device, and the like, and controls the parking support system and also functions as a control unit of the vehicle height detection device 10. The ECU 20 functions as vehicle height calculation means that receives image data from the camera 30 and horizontal distance measurement data from the sonar 40, calculates the vehicle height and inclination angle of the vehicle 1, and sends the vehicle height and inclination angle data to the related system. Is configured to do.

The camera 30 is an imaging unit that continuously captures a rear image of the vehicle 1 via an imaging lens unit 30a (see FIG. 5) as an imaging unit, and sends image data to the ECU 20. Note that the imaging unit may be a pinhole, a reflecting mirror, or the like.
The sonar 40 is an ultrasonic sensor having a predetermined directivity, and is a distance measurement unit that measures a horizontal distance from an object (measurement target) around the vehicle and sends horizontal distance measurement data to the ECU 20. The sonar 40 is disposed below the camera 30 and at a position close to the ground.

  FIG. 2 is an explanatory view of the rear portion of the vehicle 1 as viewed from above the vehicle. The camera 30 is disposed at the center in the width direction of the vehicle 1, and the optical axis Z of the imaging lens unit 30 a is directed rearward along the direction of the center axis extending in the front-rear direction of the vehicle 1. The camera 30 is arranged such that the optical axis Z faces downward from the horizontal direction h by a predetermined angle (for example, about 20 ° to 30 °). Thereby, the camera 30 images the imaging range around the rear part of the vehicle 1.

  As shown in FIG. 2, the sonar 40 is provided at four locations on the rear portion of the vehicle 1, and is disposed at two locations on both sides in the vehicle width direction with the camera 30 in between. The sonars 40a, 40b, 40c, and 40d can measure the horizontal distances to the measurement objects in the distance measurement ranges Ka, Kb, Kc, and Kd, respectively.

  In the present embodiment, four sonars 40a to 40d are provided. However, the present invention is not limited to this, and one or a plurality of sonars can be provided. In this embodiment, a sensor using ultrasonic waves is used as the distance measuring means, but the present invention is not limited to this, and a sensor using electromagnetic waves, invisible light, or the like may be used.

FIG. 3 is a configuration block diagram of the vehicle height detection device 10 of the present embodiment.
The ECU 20 receives the horizontal distance measurement data from the image processing unit 21 that performs image processing on the image data received from the camera 30, the image pattern storage unit 22 that stores the image pattern used for the image pattern matching processing, and the sonar 40, and converts them into horizontal distance data. A sonar measurement unit 23, a storage unit 24 that stores various learning values, setting values, and calculation values, and a vehicle height / tilt angle calculation unit 25 that calculates the vehicle height and the tilt angle of the vehicle 1. In addition, the sonar measurement unit 23 receives vehicle speed data from the vehicle speed sensor 52.

The image processing unit 21 serving as a parking support system sends image data to the back monitor display unit 50 including an LCD or the like. As a result, the driver can check the back of the vehicle 1 with the back monitor display unit 50 during the parking operation.
Further, the vehicle height / tilt angle calculation unit 25 sends the vehicle height / tilt angle data to the vehicle height / tilt angle utilization device 54. The vehicle height / tilt angle utilization device 54 using the vehicle height / tilt angle data is, for example, a headlight optical axis control system, a rearview mirror angle control system, a vehicle height adjustment system, a fuel gauge control system, a suspension damper system, or the like. .

FIG. 4 shows an example of image data captured by the camera 30.
This image data may be appropriately image-converted according to the lens type of the imaging lens unit 30a of the camera 30. In FIG. 4, the column 2, which is a measurement object, is imaged on the rear right side of the vehicle 1 (left side in the image data).

As described above, the camera 30 is fixed in a state of being aligned with the rear portion of the vehicle 1. Specifically, the camera 30 is the vehicle 1 in a state where only the driver gets in the driver's seat, no other occupants are in the vehicle, and no load other than the standard load is loaded (measurement reference state). Are fixed to the vehicle 1 so as to have a predetermined height and a predetermined position in the vehicle width direction. Further, in the measurement reference state, the camera 30 is aligned such that the optical axis Z (reference optical axis Z ₀ ) of the imaging lens unit 30a faces the rear of the vehicle and downward from the horizontal direction by a predetermined angle.

In the image data by the camera 30 thus aligned, the vanishing point is located at the point V ₀ (0, 0) in the image data in FIG. 4 in the measurement reference state. In the present embodiment, the vertical angle of the optical axis Z is set so that the vanishing point is included in the imaging range. The vanishing point corresponds to an infinitely far virtual point behind the vehicle 1 in the horizontal direction in the image data captured from the vehicle 1 in the measurement reference state placed on the horizontal plane.

  Also, as shown in FIG. 4, a horizontal angle X and a vertical angle (or a look-down angle) Y are assigned to each point of the image data, and the ECU 20 (image processing unit 21) The angles X and Y corresponding to each point coordinate are stored in the storage unit 24 as corresponding data.

  The left-right direction angle X is the angle in the left-right direction with respect to the optical axis Z of the camera 30. When the position of the camera 30 is used as a reference, the measurement object is moved from the optical axis Z (or vanishing point) to the left When the measurement object is located at a position separated by an angle X in the direction, the measurement object is displayed at the point of the left-right direction angle X in the image data.

The vertical angle Y is the vertical angle with respect to the optical axis of the camera 30, and when the position of the camera 30 is used as a reference, the vanishing point V ₀ (0, 0) is the origin and the vanishing point V ₀ is the reference. The elevation angle and the dip angle (looking-down angle) are the vertical angle Y. Therefore, in the measurement reference state, when the measurement object is at a position away from the vanishing point V _{0 in the} vertical direction by the angle Y, the measurement object is displayed at the point of the vertical angle Y in the image data. .

In FIG. 4, the support | pillar 2 imaged in the measurement reference | standard state is shown with the broken line. The support column 2 is installed directly on the ground on which the vehicle 1 is placed. As can be seen from FIGS. 2 and 4, the camera 30 out of the front edge of the contact portion (or lower end) of the support column 2 with the ground. The point closest to is indicated by a specific point P ₀ in the image data.

  On the other hand, the vehicle height of the vehicle 1 changes due to boarding of passengers in other seats and loading of luggage in the trunk room. Further, in general, in a passenger car such as the vehicle 1, the change in the vehicle height due to the occupant or the load is large at the rear end and hardly changes at the front end. Therefore, the change in the forward / backward inclination angle of the vehicle can be approximated to occur when the vehicle rear end rotates around the vehicle front end.

As described above, when the vehicle height changes, the optical axis Z of the camera 30 is also displaced in the vertical direction. Moreover, since the front-back inclination angle of the vehicle 1 changes with the change in the vehicle height, the optical axis direction of the camera 30 also changes slightly. For example, when the rear end of the vehicle 1 sinks and the vehicle height is lowered, the optical axis Z (or the camera 30) is also displaced to a lower position accordingly, and the optical axis Z of the camera 30 is the reference in the measurement reference state. It tilts downward from the optical axis Z ₀ (see FIG. 5). Thereby, in the image data, the support column 2 and the vanishing point move upward. In FIG. 5, the reference optical axis Z ₀ is added merely for explaining the downward tilt angle, and the vertical displacement of the camera 30 is not taken into consideration.
In FIG. 4, the support | pillar 2 imaged in the state where the vehicle height became low is shown as the continuous line. Further, the vanishing point at this time moves to the position of the virtual point V, and the specific point P ₀ of the support column 2 also moves to the point P (X, Y).

Next, based on FIG.5 and FIG.6, the calculation process of the vehicle height and inclination angle of this embodiment is demonstrated.
FIG. 5 shows the positional relationship between the vehicle 1 and the column 2 as viewed from the side. FIG. 6 shows the positional relationship between the camera 30, the sonar 40 (40c), and the column 2 in plan view. 5 and 6 show a state in which the vehicle height is lowered due to loading of luggage or the like.
Hereinafter, a case where the sonar 40c is used as the distance measuring means and the vehicle height or the like is calculated by the combination of the sonar 40c and the camera 30 will be described.

In the measurement reference state, the camera 30 is positioned at the reference ground height (or learning ground height) H ₀ (see FIG. 1). However, when the vehicle height is low, as shown in FIG. 5, the camera 30 is positioned at the ground height H, and the ground height H is slightly lower than the reference ground height H ₀ . In addition, the rear end side of the vehicle 1 is lowered and tilted at a slight tilt angle Rc. As a result, the optical axis Z (low vehicle height optical axis Z) is also inclined downward by a slight inclination angle Rc compared to the reference optical axis Z _{0 in the} measurement reference state.

  Moreover, as shown in FIG. 5, the point nearest to the camera 30 among the contact parts with the ground G of the support | pillar 2 is equivalent to the specific point P which is a predetermined part. As shown in FIG. 6, the specific point P of the column 2 is separated from the camera 30 by the horizontal distance L (second horizontal distance) in the direction in which the optical axis Z extends. Specifically, the point P is separated by a horizontal distance L with respect to a horizontal line cTL that crosses the imaging lens unit 30a of the camera 30 and is orthogonal to the optical axis Z in plan view. In the present embodiment, the lateral line cTL extends in the vehicle width direction, but may not necessarily extend in the vehicle width direction as long as it is orthogonal to the optical axis Z in plan view.

Further, as shown in FIG. 6, the horizontal distance B is a horizontal distance between the point S (sonar 40c) and the point Q (imaging lens unit 30a), and a line SQ (horizontal) in a plan view connecting the two points. The planar view angle formed by the distance B) and the horizontal line cTL is an angle β. The positional relationship data (B, β) between the camera 30 and the plurality of sonars 40 is known and stored in the storage unit 24 of the ECU 20.
The horizontal distance A between the sonar 40c and the support column 2 is measured by the sonar 40c.
The horizontal distance C is a horizontal distance of a line PQ connecting the point Q (camera 30) and the specific point P.

  As shown in FIG. 5, the point P of the column 2 is positioned downward by a substantially angle Y with respect to a line h extending in the horizontal direction when viewed from the camera 30. Specifically, the line connecting the specific point P and the point Q (imaging lens unit 30a) forms a substantially angle Y with the line h in a side view. Therefore, in the image data of FIG. 4, the specific point P appears at a substantially downward angle Y (30 ° in this case). In the present embodiment, the angle Y formed by the line h extending in the horizontal direction and the line PQ is obtained, but the line h is not necessarily used as a reference, and a line extending in another direction may be used as a reference. However, in order to use the following formula (3), it is preferable to use the line h as a reference.

Further, as shown in FIG. 6, the specific point P of the column 2 is located in the vehicle right direction (left direction from the camera 30) by an angle X from the optical axis Z with respect to the point Q in plan view. . Specifically, the optical axis Z and the line PQ (horizontal distance C) connecting the point Q and the specific point P form an angle X in plan view. Therefore, in the image data of FIG. 4, the specific point P appears at the right angle X (30 ° in this case). The line PQ (horizontal distance C) and the line cTL form an angle α (α = 90 ° −X) in plan view.
As described above, the ECU 20 (image processing unit 21) can obtain the angles X and Y by performing image processing on the image data and specifying the specific point P.

これらのうち、Ａ、Ｂ、α（＝９０°−Ｘ）、βは、ソナー４０による水平測定距離，記憶部２４に記憶された規定値，又は画像データから求められる値であるので、上記式（１）から、水平距離Ｃを算出することができる。 Based on these data, the ECU 20 (vehicle height / tilt angle calculator 25) calculates the vehicle height H and the tilt angle Rc using the following equations.
The relationship between the horizontal distance A, the horizontal distance B, the horizontal distance C, the angle α (α = 90 ° −X), and the angle β is expressed by Expression (1).

Of these, A, B, α (= 90 ° −X), and β are horizontal measurement distances by the sonar 40, prescribed values stored in the storage unit 24, or values obtained from the image data, and thus the above formula. From (1), the horizontal distance C can be calculated.

式（１）により水平距離Ｃが求められているので、式（２）から水平距離Ｌを算出することができる。 Further, the relationship between the horizontal distance L and the angle α is expressed by Expression (2).

Since the horizontal distance C is obtained from the equation (1), the horizontal distance L can be calculated from the equation (2).

  In the present embodiment, the camera 30 and the sonar 40 are arranged at different positions in plan view. However, the present invention is not limited to this, and the camera 30 and the sonar 40 may be arranged at the same position in plan view. . In this case, A = C, B = 0, β = 0 °, and the above processing can be further simplified.

  In this embodiment, the measurement object located at a position deviated from the optical axis Z in the left-right direction is used. However, the measurement object is not limited to this, and the measurement object located on the extension line of the optical axis Z in plan view. You may comprise so that only may be utilized. In this case, α = 90 ° (X = 0 °) and C = L, and the above processing can be further simplified.

  Further, the camera 30 and the sonar 40 may be arranged at the same horizontal position in a plan view and use only a measurement object located on an extension line of the optical axis Z in the plan view. In this case, α = 90 ° (X = 0 °), A = C = L, B = 0, β = 0 °, and the above processing can be further simplified.

よって、式（２）により水平距離Ｌが求められているので、式（３）からカメラ３０の地上高Ｈを算出することができる。また、車両１の所定部位の車高は、地上高Ｈ、及び当該部位とカメラ３０との位置関係データから算出することができる。 Furthermore, since the inclination angle Rc is small, the relationship between the ground height H and the horizontal distance L of the camera 30 can be approximated by Expression (3).

Therefore, since the horizontal distance L is obtained by the equation (2), the ground height H of the camera 30 can be calculated from the equation (3). In addition, the vehicle height of a predetermined part of the vehicle 1 can be calculated from the ground height H and the positional relationship data between the part and the camera 30.

なお、基準地上高Ｈ₀は、車両１が上記測定基準状態にあるときに、式（３）から算出し、記憶部２４に記憶させた学習値であってもよいし、予め設定された値であってもよい。 Furthermore, the relationship between the ground height H and the reference ground height H ₀ is expressed by Expression (4). L ₀ is a horizontal distance from the center of the front wheel to the camera 30 in the vehicle longitudinal direction of the vehicle 1. More preferably, the virtual rotation center is obtained from the suspension characteristics of the vehicle 1 and the vehicle center of gravity, and the horizontal distance from the virtual rotation center to the camera 30 is set to L ₀ .

The reference ground height H ₀ may be a learning value calculated from Equation (3) and stored in the storage unit 24 when the vehicle 1 is in the measurement reference state, or a preset value. It may be.

As a modification, the vehicle height H and the inclination angle Rc may be calculated as follows.
First, the load is gradually mounted from the measurement reference state, the vehicle height and the inclination angle are measured, and the vehicle height and the inclination angle are correlated with the ground portion looking down angle Y at each horizontal distance L, so that the correspondence data The table is stored in the storage unit 24.
In the calculation process, the ECU 20 obtains the horizontal distance L and the angle Y, and directly obtains the vehicle height H and the inclination angle Rc by referring to the correspondence data table based on the data combination. Can do.

Next, the measurement object recognition process in the present embodiment will be described.
The image pattern storage unit 22 stores a general road surface image pattern and an image pattern of an object to be measured such as a road sign pipe, a curb, and a car stop as a template.
The ECU 20 (image processing unit 21) performs image processing on the image data from the camera 30, and extracts regions having different luminance signals from the image data as candidate regions for the measurement object. Then, the ECU 20 (image processing unit 21) specifies which measurement target object the candidate area is by matching an image pattern with the candidate area. At this time, by matching the road surface image pattern with the image data, and excluding the region having a high degree of matching with the road surface image pattern from the image data, the image area is narrowed down, so that the candidate region can be identified efficiently. May be.

  Further, the ECU 20 (image processing unit 21) recognizes the lower end of the image area specified as the measurement target as the front end of the measurement target. The front end of the measurement object is a contact portion (specific point or specific region) where the measurement object contacts the ground. More preferably, among the identified contact portions, a portion closest to the camera 30 at the height of the ground is further identified. Thus, by specifying the contact portion, the specific point (or small area) corresponding to the point P in FIG. 2 is limited.

Note that the recognition accuracy of the measurement object may be improved as follows.
In the present embodiment, since the camera 30 is a single or monocular camera, an object in the image data is directly installed on the ground or is supported by another support member and floats in the air. It is difficult to distinguish between them.

  For example, since the bumper or license plate of the vehicle located behind does not touch the ground, the lower end in the image data does not become a contact portion with the ground. For this reason, a bumper and a license plate cannot be used as a measuring object having a contact portion. Further, even when a road sign or the like is installed on a step different in height from the ground on which the vehicle 1 is placed, they cannot be used as a measurement object having a contact portion for the same reason.

  Therefore, in order to improve the detection accuracy of the measurement object, it is necessary to exclude these objects from the measurement object. For this reason, when the vehicle speed is lower than the predetermined speed during the movement of the vehicle 1 (when stopped, when leaving the vehicle, etc.), two image data captured at different times slightly shifted in time are used. Can do. By comparing these two image data, the ECU 20 (image processing unit 21) can determine whether or not an object in the image data is directly installed on the ground. Specifically, by performing image processing of two image data, an object that can be recognized as the same object is specified, and whether or not the specified object is floating from the ground is determined based on the movement distance of the ground or the like. Can be determined.

  Also, the part that floats in the air like the panel part of the guard rail (however, the column part is in contact with the ground) is stored as an image pattern, and the panel part is excluded from the image data based on this image pattern. By configuring so, the detection accuracy of the measurement object may be improved.

In the present embodiment, one camera 30 is used, but a plurality of cameras 30 may be used. By using a plurality of cameras 30 in this way, it is not necessary to separately capture images at different times that are shifted in time, and it is not necessary for the vehicle 1 to move.
Furthermore, in the present embodiment, the camera 30 is monocular, but by using a stereo camera as the camera 30, the same effect as using a plurality of cameras can be obtained.

  In the present embodiment, the calculation process is performed by specifying the contact portion with the ground as the point P among the measurement objects. However, the present invention is not limited to this, and the upper end and characteristics of the specific measurement object whose dimensions are known. A specific part such as a point may be used instead. In this case, for example, by storing the dimension data including the height dimension for each image pattern (template) of the measurement object such as a sign or a curb used in the matching process, the specific part of the measurement object is specified as the specific point. Can be used. By configuring in this way, even when the contact portion of the measurement object with the ground is difficult to discriminate from the image data, the upper end, the feature point, etc., whose height dimension from the road surface is known, can be specified. By using as a point), the measurement object can be used for the calculation process.

Next, a vehicle height and inclination angle calculation method during traveling will be described.
The process described below is applied when the vehicle speed data from the vehicle speed sensor 52 indicates a speed greater than zero. Specifically, the vehicle 1 is traveling on a flat road such as an expressway. It can be suitably applied when the measurement object is not within the imaging range of the camera 30.

FIG. 7 is image data captured while traveling on a highway. In this image data, only the vertical angle is additionally displayed.
The ECU 20 (image processing unit 21) recognizes a road shoulder line, a pedestrian crossing, a center line, a roadside belt, an arrangement of reflectors, etc., which are regions extending linearly more than a predetermined length in image data by image processing, The position (coordinate in the image data) of the intersection obtained by extending these is calculated. This intersection corresponds to the vanishing point V. In the example of FIG. 7, road shoulder lines 60 a and 60 b and a lane marking line (center line) 60 c are recognized and used to identify the vanishing point V.

The ECU 20 (image processing unit 21) calculates the vertical direction angle (looking down angle) Y of the vanishing point V from the image data. In the case of FIG. 7, it is about 4 ° (> 0 °). That is, it is displaced by a predetermined angle (about 4 °) compared to the vanishing point V ₀ shown in FIG. Thereby, it can be seen that the vehicle height is slightly lower and the vehicle body is slightly inclined.
The ECU 20 (image processing unit 21) stores correspondence data between the angle Y, the vehicle height H, and the inclination angle Rc, and the vehicle height H and the inclination angle Rc from the angle Y using the correspondence data. Can be calculated.

  In this embodiment, the vanishing point is obtained. However, the present invention is not limited to this. If the horizon is identified from the image data by image processing, and the vertical angle (look-down angle) Y of the horizon is calculated, the vanishing point is obtained. The same processing as in the case of can be performed.

Next, a processing flow of the ECU 20 of the present embodiment will be described based on FIG.
This processing flow is repeated every predetermined time, and the vehicle height H, the inclination angle Rc, and the average values thereof are calculated.
The stored vehicle height H and inclination angle Rc and their average values are reset when an event (for example, engine start, door opening / closing, etc.) that may change the vehicle height and inclination angle occurs. For example, there is a possibility that an occupant gets on and off, loads and unloads, etc. before starting the engine or opening and closing the door, so that the vehicle height and the inclination angle may change. These events can be determined by the ECU 20 receiving an engine start signal, a door opening / closing signal, and the like. After the reset, every time the vehicle 1 moves, stops and departs, the following processing flow is repeatedly performed to newly calculate and store the vehicle height H and the inclination angle Rc and their average values. .

First, the ECU 20 (sonar measurement unit 23) determines whether or not the vehicle 1 has stopped based on the vehicle speed data from the vehicle speed sensor 52 (step S1).
If the vehicle 1 has stopped (step S1; Yes), ECU20 (sonar measurement part 23) will acquire horizontal distance measurement data from each sonar 40a-40d (step S2).

  From the acquired horizontal distance measurement data, the ECU 20 (sonar measuring unit 23) calculates horizontal distance data, and based on this, determines whether or not there is an object within a predetermined horizontal distance from each sonar 40 (step). S3).

If no object is detected within the predetermined horizontal distance (step S3; No), the process is terminated, and the process of step S1 is performed again after a predetermined repetition time.
On the other hand, when an object is detected (step S3; Yes), the ECU 20 (image processing unit 21) acquires image data from the camera 30 at the time of horizontal distance measurement (step S4).

  When an object is detected, one or more sonars 40 that have detected the object are specified. When there are a plurality of sonars 40 that specify the object, the following calculation processing is performed with a plurality of combinations of the detected sonars 40 and the cameras 30, and a plurality of vehicle heights H and inclination angles Rc are calculated. When a plurality of objects are detected, the vehicle height H and the inclination angle Rc are calculated for each object. Thereby, the vehicle height H, the inclination angle Rc, and the average values of these can be calculated with higher accuracy.

Based on the acquired image data, the ECU 20 (image processing unit 21) performs image processing for specifying the measurement object (step S5). In this image processing, the ECU 20 extracts regions with different luminance (candidate regions for the measurement object) from the image data, performs matching between the candidate regions and the image pattern stored in the image pattern storage unit 22, Thereby, it is specified which measurement object (marker, curbstone, etc.) the candidate region is. Further, the ECU 20 specifies the front end of the specified measurement object (that is, the contact portion (specific point) with the ground).
In addition, after extracting a candidate area | region, matching with an image pattern does not necessarily need to be performed. When matching is not performed, the ECU 20 (image processing unit 21) identifies the extracted candidate area as a measurement object and identifies the front end.

  Next, the ECU 20 (image processing unit 21) specifies the coordinate position of the front end (specific point) of the specified measurement object in the image data, and determines the measurement target from the allocation data of the coordinate position of the image data and the vertical angle. The vertical angle Y of the front end of the object is obtained (step S6). At this time, the ECU 20 (image processing unit 21) also obtains the left-right direction angle X of the front end of the measurement object at the same time.

  Based on the obtained vertical angle Y and the horizontal distance A to the measurement object measured by the sonar 40, the ECU 20 (image processing unit 21) determines whether the obtained vertical angle Y is reasonable. It is determined whether or not (step S7). By this process, it is possible to detect misidentification of the measurement object, and when it is misidentified (step S7; No), the process is terminated.

  In this determination process, it is determined whether the vertical angle Y is within a reasonable range based on the relationship between the horizontal distance A and the vertical angle Y. For example, by setting a numerical value range that the vertical angle can take for each horizontal distance, if the obtained vertical angle is out of this range, it is determined that the measurement object is misidentified. be able to. In a specific example, when the measurement object is placed on a step, the vertical angle is below the set range.

If the vertical angle Y is reasonable (step S7; Yes), the ECU 20 (vehicle height / tilt angle calculator 25) calculates the vehicle height H and the vehicle body tilt angle Rc (step S8). The vehicle height / tilt angle calculation unit 25 includes the horizontal distance A acquired from the sonar measurement unit 23, the horizontal angle X and vertical angle Y obtained by the image processing unit 21, and the camera 30 acquired from the storage unit 24. Vehicle height based on the above formulas (1) to (4) using the positional relationship data (B, β), the reference ground height H ₀ , the vehicle dimension data (L ₀ ), etc. H and the inclination angle Rc are calculated.

When the vehicle height H and the inclination angle R are calculated, the ECU 20 (vehicle height / inclination angle calculation unit 25) stores these calculated values in the storage unit 24 (step S9).
Note that if the calculated vehicle height H and the inclination angle Rc are statistically significantly different from the values stored so far, the measurement object may be misidentified, so such calculated values are excluded. However, it may not be stored in the storage unit 24.

The ECU 20 (vehicle height / inclination angle calculation unit 25) uses a plurality of calculated values (vehicle height H and inclination angle Rc) stored in the storage unit 24 through the repeated processing so far, and averages these values. (Or median or the like) is also calculated and stored (step S10).
Then, the ECU 20 (vehicle height / tilt angle calculation unit 25) transmits the obtained average values of the vehicle height and the tilt angle to various devices using the vehicle height / tilt angle (step S11), and ends the process.

  In the present embodiment, depending on the road surface condition where the vehicle 1 is placed, the calculated vehicle height H and the inclination angle Rc may include an error. For example, when the road surface has wrinkles or unevenness, the error becomes large. Therefore, this processing flow is repeatedly performed using different measurement objects, the vehicle height H and the inclination angle Rc are obtained each time in step S9, and these average values are calculated in step S10, thereby calculating by averaging. The accuracy of the value can be improved.

  On the other hand, if the vehicle 1 is not stopped in the process of step S1 (step S1; No), the ECU 20 (image processing unit 21) acquires image data from the camera 30, and based on this image data, the above-described image data is obtained. Thus, the vanishing point is specified (step S12).

Then, the ECU (vehicle height / tilt angle calculator 25) calculates the vehicle height H and the tilt angle Rc of the vehicle 1 based on the vertical position of the vanishing point (step S13). Even in this case, if the calculated value is not statistically significant as compared with the stored value, the calculated value can be excluded.
Next, the ECU 20 (vehicle height / inclination angle calculation unit 25) transmits the calculated vehicle height and inclination angle to the vehicle height / inclination angle utilization device (step S11), and ends the process.

  Note that the processing of steps S2 to S11 may also be applied when the vehicle speed data from the vehicle speed sensor 52 indicates a speed greater than zero. Further, the processes of steps S12 and S13 can be suitably applied when the vehicle 1 is traveling on a flat road such as an expressway and the measurement object is not within the imaging range of the camera 30.

  As described above, the vehicle height detection device 10 according to the present embodiment adds software for performing additional processing to the ECU 20 using the back monitor camera 30, the sonar 40, and the ECU 20 of the existing parking assistance system. It is possible to calculate the vehicle height H and the inclination angle Rc simply by doing this, and it can be realized at low cost. Thereby, since it is not necessary to separately provide a vehicle height sensor such as an ultrasonic sensor for vehicle height detection, the weight and cost of the vehicle 1 can be reduced.

  Furthermore, when a vehicle height sensor is provided separately, the vehicle height sensor is disposed near the ground so as to face the ground, so that the vehicle height sensor may be damaged by stepping stones, dirt, etc. There is a risk of malfunctions such as inability to measure by However, in this embodiment, it is not necessary to provide a separate vehicle height sensor, and the camera 30 and the sonar 40 to be used are not installed so as to face the ground, so that there is a problem like the conventional vehicle height sensor. Occurrence can be suppressed.

  In the present embodiment, the calculated values of the vehicle height and the inclination angle can be obtained from each combination of any of the plurality of sonars 40 and the camera 30. Thus, by obtaining a plurality of sets of calculated values, it is possible to improve the calculation accuracy.

  In the above embodiment, the vehicle height H and the inclination angle Rc are calculated from the measurement object behind the vehicle using the camera 30 and the sonar 40 installed at the rear part of the vehicle 1. Cameras and sonar may also be provided at the front and left and right sides of the vehicle 1 to calculate the vehicle height H and the inclination angle Rc in the same manner. Thus, the vehicle height and the inclination angle can be calculated more accurately by measuring at the rear portion, the front portion, and the left and right side portions of the vehicle 1.

1 vehicle 2 prop (measurement object)
DESCRIPTION OF SYMBOLS 10 Vehicle height detection apparatus 21 Image processing part 22 Image pattern memory | storage part 23 Sonar measurement part 24 Memory | storage part 25 Vehicle height and inclination-angle calculation part 30 Camera 30a Imaging lens part 40, 40a-40d Sonar

Claims (3)

In the vehicle height detection device that detects the vehicle height,
A distance measuring means fixed to the vehicle body and measuring a horizontal distance to a measurement object around the vehicle;
Imaging means fixed to the vehicle body and imaging the measurement object around the vehicle;
Based on the image data of the predetermined part of the measured object, the horizontal distance, and the positional relationship data between the distance measuring unit and the imaging unit, the ground height of the imaging unit with respect to the predetermined part of the measurement object is calculated. Vehicle height calculating means for calculating and calculating the vehicle height from the ground height ,
The vehicle height calculation means calculates the vertical angle of the predetermined part as viewed from the imaging part of the imaging means based on the image data, and based on the horizontal distance and the positional relationship data, Calculating a second horizontal distance between the imaging unit in the optical axis direction of the imaging unit and the predetermined unit, and calculating the ground height using the vertical angle and the second horizontal distance. A vehicle height detection device.   The vehicle height detection device according to claim 1, wherein the predetermined part of the measurement object is a contact part of the measurement object with the ground. The vehicle height calculation means calculates a horizontal angle of a predetermined part of the measurement object viewed from the imaging unit of the imaging means based on the image data, and further uses the horizontal angle to perform the second The vehicle height detection device according to claim 1 , wherein a horizontal distance is calculated.

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